EFFECTS OF CARNOSINE AND RELATED-COMPOUNDS ON GENERATION OF FREE OXYGEN SPECIES - A COMPARATIVE-STUDY

The effect of carnosine and related compounds on the luminol- and lucigenin-dependent luminescence of rabbit leukocytes, activated by BaSO4, has been studied, Carnosine was found to modify BaSO4-induced chemiluminescence of leukocytes via suppression of hypochlorous anion generation with simultaneous stimulation the system of oxygen superoxide anion, Additionally to this effect carnosine prevents enzymic dismutation of O-2(.). Anserine, acetylanserine, and homocarnosine also possess the ability to activate O-2(.) production by leukocytes, The effect is not inherent to imidazole used in the same concentrations. Suppression of myeloperoxidase reaction by carnosine and related compounds is explained by both inhibiting action on the enzyme itself, and direct neutralization of hypochlorous anion due to formation of stable chloroamine complexes, Methylation of carnosine at N-1 nitrogen of imidazole ring, leading to anserine, forced inhibition of myeloperoxidase system, whereas its acetylation at the free beta-amino group weakened this effect.